From 88e97a93342c0b9e835d510921e7b2df8547d1bd Mon Sep 17 00:00:00 2001 From: Gerrit Renker Date: Thu, 4 Sep 2008 07:30:19 +0200 Subject: [PATCH] dccp ccid-3: Update the RX history records in one place This patch is a requirement for enabling ECN support later on. With that change in mind, the following preparations are done: * renamed handle_loss() into congestion_event() since it returns true when a congestion event happens (it will eventually also take care of ECN packets); * lets tfrc_rx_congestion_event() always update the RX history records, since this routine needs to be called for each non-duplicate packet anyway; * made all involved boolean-type functions to have return type `bool'; Updating the RX history records is now only necessary for the packets received up to sending the first feedback. The receiver code becomes again simpler. Signed-off-by: Gerrit Renker --- net/dccp/ccids/ccid3.c | 37 +++++++++-------------------- net/dccp/ccids/lib/loss_interval.c | 10 ++++---- net/dccp/ccids/lib/loss_interval.h | 2 +- net/dccp/ccids/lib/packet_history.c | 37 ++++++++++++++--------------- net/dccp/ccids/lib/packet_history.h | 10 ++++---- 5 files changed, 40 insertions(+), 56 deletions(-) diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c index f2f9514dbad..aca072b3eda 100644 --- a/net/dccp/ccids/ccid3.c +++ b/net/dccp/ccids/ccid3.c @@ -657,41 +657,26 @@ failed: static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb) { struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk); - enum ccid3_fback_type do_feedback = CCID3_FBACK_NONE; const u64 ndp = dccp_sk(sk)->dccps_options_received.dccpor_ndp; const bool is_data_packet = dccp_data_packet(skb); /* * Perform loss detection and handle pending losses */ - if (tfrc_rx_handle_loss(&hcrx->hist, &hcrx->li_hist, - skb, ndp, ccid3_first_li, sk)) { - do_feedback = CCID3_FBACK_PARAM_CHANGE; - goto done_receiving; - } - - if (unlikely(hcrx->feedback == CCID3_FBACK_NONE)) { - if (is_data_packet) - do_feedback = CCID3_FBACK_INITIAL; - goto update_records; - } - - if (tfrc_rx_hist_loss_pending(&hcrx->hist)) - return; /* done receiving */ - + if (tfrc_rx_congestion_event(&hcrx->hist, &hcrx->li_hist, + skb, ndp, ccid3_first_li, sk)) + ccid3_hc_rx_send_feedback(sk, skb, CCID3_FBACK_PARAM_CHANGE); + /* + * Feedback for first non-empty data packet (RFC 3448, 6.3) + */ + else if (unlikely(hcrx->feedback == CCID3_FBACK_NONE && is_data_packet)) + ccid3_hc_rx_send_feedback(sk, skb, CCID3_FBACK_INITIAL); /* * Check if the periodic once-per-RTT feedback is due; RFC 4342, 10.3 */ - if (is_data_packet && - SUB16(dccp_hdr(skb)->dccph_ccval, hcrx->last_counter) > 3) - do_feedback = CCID3_FBACK_PERIODIC; - -update_records: - tfrc_rx_hist_add_packet(&hcrx->hist, skb, ndp); - -done_receiving: - if (do_feedback) - ccid3_hc_rx_send_feedback(sk, skb, do_feedback); + else if (!tfrc_rx_hist_loss_pending(&hcrx->hist) && is_data_packet && + SUB16(dccp_hdr(skb)->dccph_ccval, hcrx->last_counter) > 3) + ccid3_hc_rx_send_feedback(sk, skb, CCID3_FBACK_PERIODIC); } static int ccid3_hc_rx_init(struct ccid *ccid, struct sock *sk) diff --git a/net/dccp/ccids/lib/loss_interval.c b/net/dccp/ccids/lib/loss_interval.c index fe5c2a31c77..b1ae8f8259e 100644 --- a/net/dccp/ccids/lib/loss_interval.c +++ b/net/dccp/ccids/lib/loss_interval.c @@ -140,18 +140,18 @@ static inline u8 tfrc_lh_is_new_loss(struct tfrc_loss_interval *cur, * @sk: Used by @calc_first_li in caller-specific way (subtyping) * Updates I_mean and returns 1 if a new interval has in fact been added to @lh. */ -int tfrc_lh_interval_add(struct tfrc_loss_hist *lh, struct tfrc_rx_hist *rh, - u32 (*calc_first_li)(struct sock *), struct sock *sk) +bool tfrc_lh_interval_add(struct tfrc_loss_hist *lh, struct tfrc_rx_hist *rh, + u32 (*calc_first_li)(struct sock *), struct sock *sk) { struct tfrc_loss_interval *cur = tfrc_lh_peek(lh), *new; if (cur != NULL && !tfrc_lh_is_new_loss(cur, tfrc_rx_hist_loss_prev(rh))) - return 0; + return false; new = tfrc_lh_demand_next(lh); if (unlikely(new == NULL)) { DCCP_CRIT("Cannot allocate/add loss record."); - return 0; + return false; } new->li_seqno = tfrc_rx_hist_loss_prev(rh)->tfrchrx_seqno; @@ -169,7 +169,7 @@ int tfrc_lh_interval_add(struct tfrc_loss_hist *lh, struct tfrc_rx_hist *rh, tfrc_lh_calc_i_mean(lh); } - return 1; + return true; } EXPORT_SYMBOL_GPL(tfrc_lh_interval_add); diff --git a/net/dccp/ccids/lib/loss_interval.h b/net/dccp/ccids/lib/loss_interval.h index f101ae2cf52..d08a226db43 100644 --- a/net/dccp/ccids/lib/loss_interval.h +++ b/net/dccp/ccids/lib/loss_interval.h @@ -67,7 +67,7 @@ static inline u8 tfrc_lh_length(struct tfrc_loss_hist *lh) struct tfrc_rx_hist; -extern int tfrc_lh_interval_add(struct tfrc_loss_hist *, struct tfrc_rx_hist *, +extern bool tfrc_lh_interval_add(struct tfrc_loss_hist *, struct tfrc_rx_hist *, u32 (*first_li)(struct sock *), struct sock *); extern void tfrc_lh_update_i_mean(struct tfrc_loss_hist *lh, struct sk_buff *); extern void tfrc_lh_cleanup(struct tfrc_loss_hist *lh); diff --git a/net/dccp/ccids/lib/packet_history.c b/net/dccp/ccids/lib/packet_history.c index 547ad098ea6..cce9f03bda3 100644 --- a/net/dccp/ccids/lib/packet_history.c +++ b/net/dccp/ccids/lib/packet_history.c @@ -192,10 +192,8 @@ static void __do_track_loss(struct tfrc_rx_hist *h, struct sk_buff *skb, u64 n1) u64 s0 = tfrc_rx_hist_loss_prev(h)->tfrchrx_seqno, s1 = DCCP_SKB_CB(skb)->dccpd_seq; - if (!dccp_loss_free(s0, s1, n1)) { /* gap between S0 and S1 */ + if (!dccp_loss_free(s0, s1, n1)) /* gap between S0 and S1 */ h->loss_count = 1; - tfrc_rx_hist_entry_from_skb(tfrc_rx_hist_entry(h, 1), skb, n1); - } } static void __one_after_loss(struct tfrc_rx_hist *h, struct sk_buff *skb, u32 n2) @@ -328,13 +326,13 @@ static void __three_after_loss(struct tfrc_rx_hist *h) } /** - * tfrc_rx_handle_loss - Loss detection and further processing - * @h: The non-empty RX history object - * @lh: Loss Intervals database to update - * @skb: Currently received packet - * @ndp: The NDP count belonging to @skb - * @calc_first_li: Caller-dependent computation of first loss interval in @lh - * @sk: Used by @calc_first_li (see tfrc_lh_interval_add) + * tfrc_rx_congestion_event - Loss detection and further processing + * @h: The non-empty RX history object + * @lh: Loss Intervals database to update + * @skb: Currently received packet + * @ndp: The NDP count belonging to @skb + * @first_li: Caller-dependent computation of first loss interval in @lh + * @sk: Used by @calc_first_li (see tfrc_lh_interval_add) * Chooses action according to pending loss, updates LI database when a new * loss was detected, and does required post-processing. Returns 1 when caller * should send feedback, 0 otherwise. @@ -342,12 +340,12 @@ static void __three_after_loss(struct tfrc_rx_hist *h) * records accordingly, the caller should not perform any more RX history * operations when loss_count is greater than 0 after calling this function. */ -int tfrc_rx_handle_loss(struct tfrc_rx_hist *h, - struct tfrc_loss_hist *lh, - struct sk_buff *skb, const u64 ndp, - u32 (*calc_first_li)(struct sock *), struct sock *sk) +bool tfrc_rx_congestion_event(struct tfrc_rx_hist *h, + struct tfrc_loss_hist *lh, + struct sk_buff *skb, const u64 ndp, + u32 (*first_li)(struct sock *), struct sock *sk) { - int is_new_loss = 0; + bool new_event = false; if (tfrc_rx_hist_duplicate(h, skb)) return 0; @@ -355,6 +353,7 @@ int tfrc_rx_handle_loss(struct tfrc_rx_hist *h, if (h->loss_count == 0) { __do_track_loss(h, skb, ndp); tfrc_rx_hist_sample_rtt(h, skb); + tfrc_rx_hist_add_packet(h, skb, ndp); } else if (h->loss_count == 1) { __one_after_loss(h, skb, ndp); } else if (h->loss_count != 2) { @@ -363,7 +362,7 @@ int tfrc_rx_handle_loss(struct tfrc_rx_hist *h, /* * Update Loss Interval database and recycle RX records */ - is_new_loss = tfrc_lh_interval_add(lh, h, calc_first_li, sk); + new_event = tfrc_lh_interval_add(lh, h, first_li, sk); __three_after_loss(h); } @@ -378,12 +377,12 @@ int tfrc_rx_handle_loss(struct tfrc_rx_hist *h, } /* RFC 3448, 6.1: update I_0, whose growth implies p <= p_prev */ - if (!is_new_loss) + if (!new_event) tfrc_lh_update_i_mean(lh, skb); - return is_new_loss; + return new_event; } -EXPORT_SYMBOL_GPL(tfrc_rx_handle_loss); +EXPORT_SYMBOL_GPL(tfrc_rx_congestion_event); /* Compute the sending rate X_recv measured between feedback intervals */ u32 tfrc_rx_hist_x_recv(struct tfrc_rx_hist *h, const u32 last_x_recv) diff --git a/net/dccp/ccids/lib/packet_history.h b/net/dccp/ccids/lib/packet_history.h index 6552be63cb0..555e65cd73a 100644 --- a/net/dccp/ccids/lib/packet_history.h +++ b/net/dccp/ccids/lib/packet_history.h @@ -186,11 +186,11 @@ extern void tfrc_rx_hist_add_packet(struct tfrc_rx_hist *h, extern int tfrc_rx_hist_duplicate(struct tfrc_rx_hist *h, struct sk_buff *skb); struct tfrc_loss_hist; -extern int tfrc_rx_handle_loss(struct tfrc_rx_hist *h, - struct tfrc_loss_hist *lh, - struct sk_buff *skb, const u64 ndp, - u32 (*first_li)(struct sock *sk), - struct sock *sk); +extern bool tfrc_rx_congestion_event(struct tfrc_rx_hist *h, + struct tfrc_loss_hist *lh, + struct sk_buff *skb, const u64 ndp, + u32 (*first_li)(struct sock *sk), + struct sock *sk); extern void tfrc_rx_hist_sample_rtt(struct tfrc_rx_hist *h, const struct sk_buff *skb); extern int tfrc_rx_hist_init(struct tfrc_rx_hist *h, struct sock *sk);